[src/trunk]: src/bin/csh switch to a backtracking instead of a recursive patt...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/61eda1b2e32f
branches:  trunk
changeset: 823595:61eda1b2e32f
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Apr 27 18:50:34 2017 +0000

description:
switch to a backtracking instead of a recursive pattern matcher.

diffstat:

 bin/csh/glob.c |  100 +++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 59 insertions(+), 41 deletions(-)

diffs (140 lines):

diff -r 6edef6fbd2a1 -r 61eda1b2e32f bin/csh/glob.c
--- a/bin/csh/glob.c    Thu Apr 27 17:32:26 2017 +0000
+++ b/bin/csh/glob.c    Thu Apr 27 18:50:34 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: glob.c,v 1.27 2013/07/16 17:47:43 christos Exp $ */
+/* $NetBSD: glob.c,v 1.28 2017/04/27 18:50:34 christos Exp $ */
 
 /*-
  * Copyright (c) 1980, 1991, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)glob.c     8.1 (Berkeley) 5/31/93";
 #else
-__RCSID("$NetBSD: glob.c,v 1.27 2013/07/16 17:47:43 christos Exp $");
+__RCSID("$NetBSD: glob.c,v 1.28 2017/04/27 18:50:34 christos Exp $");
 #endif
 #endif /* not lint */
 
@@ -89,7 +89,7 @@
 static Char **globexpand(Char **);
 static int globbrace(Char *, Char *, Char ***);
 static void expbrace(Char ***, Char ***, size_t);
-static int pmatch(Char *, Char *);
+static int pmatch(const Char *, const Char *);
 static void pword(void);
 static void psave(int);
 static void backeval(Char *, int);
@@ -818,56 +818,74 @@
 } 
 
 static int
-pmatch(Char *string, Char *pattern)
+pmatch(const Char *name, const Char *pat)
 {
     int match, negate_range;
-    Char patternc, rangec, stringc;
+    Char patc, namec, c;
+    const Char *nameNext, *nameStart, *nameEnd, *patNext;
+
+    nameNext = nameStart = name;
+    patNext = pat;
+    nameEnd = NULL;
 
-    for (;; ++string) {
-       stringc = *string & TRIM;
-       patternc = *pattern++;
-       switch (patternc) {
+    for (;;) {
+       namec = *name & TRIM;
+       if (namec == 0)
+           nameEnd = name;
+       patc = *pat;
+       switch (patc) {
        case 0:
-           return (stringc == 0);
+           if (namec == 0)
+               return 1;
+           break;
        case '?':
-           if (stringc == 0)
-               return (0);
-           break;
+           if (namec == 0)
+               break;
+           pat++;
+           name++;
+           continue;
        case '*':
-           if (!*pattern)
-               return (1);
-           while (*string)
-               if (Gmatch(string++, pattern))
-                   return (1);
-           return (0);
+           while ((pat[1] & TRIM) == '*')
+               pat++;
+           patNext = pat;
+           nameNext = name + 1;
+           pat++;
+           continue;
        case '[':
            match = 0;
-           if ((negate_range = (*pattern == '^')) != 0)
-               pattern++;
-           while ((rangec = *pattern++) != '\0') {
-               if (rangec == ']')
-                   break;
-               if (match)
-                   continue;
-               if (rangec == '-' && *(pattern-2) != '[' && *pattern  != ']') {
-                   match = (stringc <= (*pattern & TRIM) &&
-                             (*(pattern-2) & TRIM) <= stringc);
-                   pattern++;
-               }
-               else 
-                   match = (stringc == (rangec & TRIM));
+           if (namec == 0)
+               break;
+           pat++;
+           name++;
+           if ((negate_range = (*pat == '^')) != 0)
+               pat++;
+           while ((c = *pat++) != ']') {
+               c &= TRIM;
+               if (*pat == '-') {
+                   if (c <= namec && namec <= (pat[1] & TRIM))
+                       match = 1;
+                   pat += 2;
+               } else if (c == namec)
+                   match = 1;
+               else if (c == 0)
+                   stderror(ERR_NAME | ERR_MISSING, ']');
            }
-           if (rangec == 0)
-               stderror(ERR_NAME | ERR_MISSING, ']');
            if (match == negate_range)
-               return (0);
-           break;
+               break;
+           continue;
        default:
-           if ((patternc & TRIM) != stringc)
-               return (0);
-           break;
-
+           if ((patc & TRIM) != namec)
+               break;
+           pat++;
+           name++;
+           continue;
        }
+       if (nameNext != nameStart && (nameEnd == NULL || nameNext <= nameEnd)) {
+           pat = patNext;
+           name = nameNext;
+           continue;
+       }
+       return 0;
     }
 }